Railway-train-control system.



1 c. McD ONALD.

RAILWAY TRAIN CONTROL SYSTEM. APPLICATION FILED AUG-27,1915.

1,205,462. Patented. Nov. 21, 1916.

. v 3 SHEETSSHEET l.

, lNl/ENTOI? I. C. McDONALU.

RAILWAY TRAIN C(ENTROL SYSTEM.

APPLICATION FILED AUG-2T, x915.

.;QQ5,%2 a I Patented Nov. 21, 1916.

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Jim

5 wvewroz 3513 A flt tozmeq I. C. McDONALD.

RAILWAY TRAIN.CONTROL SYSTEM.

APPLICATION FILED AUG-27, I9I5.

1 05,462, Patented Nov. 21, 1916.

3 SHEETS-SHEET 3.

Wu messes:

3 vwewtoz JOHN C. MCDONALD, OF NEW YORK, N. Y.

RAILWAY-TRAIN-CONTROL SYSTEM.

Specification of Letters Patent.

Application filed August 27, 1915. Serial No. 47,581.

7. all whom it In (11 concern:

Be it known that 1, JOHN C. MCDONALD, a citizen of the United States ofAmerica, and a resident of New York, in the county of New York and Stateof New York, have invented a certain new and useful Railwaylrain-ControlSystem, of which the following is a specification.

My invention relates to improvements in railway train control'systemsand particularly to combined train-stopping and speedcontrol systems.

I have illust'ated my invention particularly as applied to electricroads wherein the trains are operated by electric motors derivingcurrent from a third rail or other conductor other than the track rails;but it will be apparent that the system is equally applicable to roadswhereon the trains are operated by steam or other motive power otherthan electricity.

In the following descrlption I will generally refer to the conductorfrom which the trains receive current for motive power and for control,as the third-rail; but it will be understood that any other conductor,for example, an over-head trolley wire, may be substituted for what is,strictly speaking, a third rail, without departure from my invention.

My invention comprises controlling circuits and instruments, the latterbeing, generally, of the nature of relays, and I have illustrated thetrack relay of each block as controlled by track circuits; though otherwell known means for the control of such relays may obviouslybeemployed.

My invention further comprises train circuits and instruments carried bythe trains passing over the track.

The objects of my invention are to facilitate the operation of railways;to reduce the liability to collision; to provide simple and effectivemeans for the control of speed; to

provide simple and effective means for positively stopping trains; toprevent entry of trains into blocks which are already occupied .tomaintain proper block intervals between trains with provisionpermitting, un-

der exceptional circumstances, (such for example as the stalling of atram ahead) the passage of a train 1nto a block already occopied; tomake the system readily applicable to existing railways; and generallyto make the circuits and apparatus of the system simple and reliable,and to cause such circuits and apparatus to afford ample protectlon.

I w1ll now proceed to describe my invention with reference to theaccompanying drawmgs, and will then point out the novel features inclaims.

Figure 1 is a diagrammatic View showing circuits and instruments for onetrack of a double track railway, t e direction of normal progress alongsuch track being indicated by an arrow. Fig. 2 is a diagram of traincircuits which may. be employed in connection with the circuits shown inFig. 1. Fig. 3 is a diagrammatic view similar to Fig.1, showing howeveranarrangement employing alternating current for propulsion current anddirect current for train-control current. Fig. l is a diagram of traincircuits which may be employed in connection with the circuits shown inFig. 3. Fig. 5 is a diagrammatic view similar'to Figs. 1 and 3, butshowing an arrangement employing alternating current of one frequencyfor propulsion and alternating current of another he quency for traincontrol current, and Fig. 6

is a diagram of train circuits which may be Patented Nov. 21 1916.

tions, such sections being insulated from.

each other. The length of such track sections will depend upon traflicconditions and may be determined readily by those skilled .in the art.-The third rail is also, preferably, divided into block sections,corresponding generally to the division of the track rail -into blocksections as above described, the sections of the third rail being notnecessarily, however, absolutely co-terminous with the correspondingsections of the t 'ack rail.

Referring now to Fig. 1: R and R designate trackrails of which R isshown divided into block sections 2, 3, 4, etc. For each such blockthere is a corresponding t 'ack relay TR', TR, etc. I have notillustrated atrack relay for block 2, but it will be understood that thesame instruments and circuits are'provided for each block. For eachblock there is also. another relay. commonly termed a line relay. anddesignated by reference charcters L, If, etc. (It

will be understood that the term i'elay is employed herein in a genericsense, as inthe wheels and axles of a train present on the correspondingblock, so as to deenergize the corresponding track relays T3 TR, etc. Tdesignates the third rail, and F a direct current feeder for the severalsections of this third rail. In the system asillustrated in Figs. 1 and2, the use of direct current for motive power is contemplated, and theuse of alternating current for train control is contemplated, andtherefore the sections of the third rail T are connected by inductivebonds I 1*, etc., which permit the passage ofthe direct power current,but substantially prevent the passage of the alternating train controlcurrent. 0 designates a common return conductor for the train controlcircuits and S S", etc, designate transformers, one for each blocksection,

supplying alternating current for the train control circuits. SXdesignates the conductor supplying the alternating current to theprimary coils of these transformers.

The line relays L L etc., are time element or delay action relays; thatis to say, a predetermined interval of time is required for the closingof contact by these relays following the energization of their magnets.Such delay action relays are well known, and I do not limit myself tothe use of any particular type of such relay; but as a diagrammaticillustration of the delay action character of these relays I have shownthe armature of each such relay as provided with a. controlling dash-potD. It is well known that by means of such a dash-pot employin'r eitherliquid or air as the impeding medium, the time required for the closingof contact by the relay may be anything desired within reasonablelimits.

Each of the relays TR, TR, etc, has three independent armature contactpoints (L, I), and c, with corresponding fixed contact points.

The circuits will be best understood by dcscribing the operation of thesystem.

Suppose a train to enter block '3 from block As soon as the wheels ofthat train enter block 3, the track circuit controlling relay TR will beshunted, dele'nergizing the magnet of relay TR, and permitting itsarmature contacts to drop back. Upon the decnergization of relay TR acircuit will be completed from point 8 of common return conductor 0through armature contact 0-, of relay Tit and the back contact of thatarmature through conductor I) and the magnet of line relay L, andthence, through conductor C, to the 1: armature of a track relay ofablock ahead (in contact of relay TR, and the corresponding frontcontact stop, and the armature contact (Z of the corresponding relay Land the corresponding rear contact, through the secondar windin s of thetransformer S to return'conductor O and thence back to starting point 8.By the completion of this alternating current circuit the relay L willbe energized (it will be understood that these relays L L5, etc, arealternating cur-* rent relays as well as delay action relays) andtherefore the armatures of relay L will be attracted; but since thisrelay L is a delay'ac'tion relay, a predetermined interval of time willelapse following the energization' of the magnet of this relay L, beforecontact is made with the front contact of that relay L". Should thetrain so entering block 3 proceed through that block at a speed greaterthan that for which delay action relay L has been timed, such train willreach the entrance of block L before the front contact of relay L hasbeen made; in which case (since the front contact of this relay Lcontrols the supply of alternating current from secondary s oftransformer S to section-T of the third rail, and to the traclcrail Rthere will be no alternating current on third rail section T and,therefore, by means hereinafter described the train will be brought torest at the entrance of block 4. If, however, the train in block 3proceeds'through that block at a speednot greater than 'that'for whichrelay L. has been set, by the time that train has reached the entranceof block 4 relay L will have closed its front contact, and thereby'alternating current from secondary coil .9 of the transformer S will besupplied through the front contact of that relay L to the third railsection T thereby permitting the train to proceed, as hereinafterdescribed with reference to the circuits and instruments carried by thetrain. But now suppose that at the time the train starts to pass fromblock 2 into block 3, block 6 is occupied. in that event, when the firstmentioned train starts to enter block 3, the umguet of track relay TRwill be dener gizcd, and the circuit of conductor C through the 1'armature of relay TR, and the front contact corresponding to thatarmature, will be broken; consequently, the magnet of relay L will notbe energized upon the entry of the first mentioned train into block 3,and, when the train proceeds through block 3 and reaches the entrance ofblock 4, relay L will not have closed thealternating current circuit tothe third rail section '1 (supposing block 6 still to be'occupicd, ornot to have been vacated for a time corresponding to that to which relayswitches 18 aml 18, respectively.

L has been set) and therefore the train seeking to enter block 4 fromblock 3 will be brought to rest by the means hereinafter described.

.\Vl1en the first mentioned train passes from block 2 into block 3, themagnet of relay L will, in general, already have been energized and thealternating circuit from secondary s of transformer S will have beenapplied to third rail section T through the front contact of relay Lsimilarly, when the train enters block T* relay L will already have beenenergized by the action of relay T R as previously described; whenthetrain has passed completely into block 4 the 7) armature of relay'TRwill maintain the circuit through the magnet of relay L such provisionbeing necessary since, when the train passes completely out of block 3the magnet of relay TR will be energized and its armature contacts heldin attracted position. Vhen the train has passed completely out of block1 the magnet of relay TR will be energized in turn, its armature contactpoints held in attracted position, and, therefore, the magnet of relay Lwill be' deenergized.

It will be seen that by the expedient of extending backward the circuitof each line relay L, L*, etc, to a contact of a track' relaycorresponding to a preceding block, I obtain a control of the speed ofthe train passing through that preceding block; for should the trainexceed the predetermined speed it will be arrested upon entry into .theblock to which the particular line relay under consideration belongs.

Referring now to Fig. 2, showing the in-. struments and circuitsprovided on a car or cars of the train to be controlled: 99 designatecontact shoes adapted to make contact with the third rail T, 10designates the train line bus. having in it an impedance bond 10. and 11designates a conductor connected to the contact shoes 9 and alsoconnected to the train line bus through the impedance bond 10. 12designates the air brake line, 13 a circuit breaker, controlling thecircuit 1415 leading to the circuit controller of the car, and 1Gdesignates a combined electrically operated valve and relay which, as avalve, controls the air brake line 12. At the operating station orstations of the car I provide a combined valve and switch 17. or 17,also another combined valve and switch 18 or 19. In most cases motorcars, electric loco motives, etc, are arranged for operation from eitherend. and therefore two operat ing positions are provided: consequently,in Fig. '2, l have shown two valve switches 17 and 17 respectively, alsotwo other valve I have shown the valve 17in the open or runningposition, that being the position which that a ry valve should occupywhen the car is to be controlled from the end at which that valve 17 islocatedgand correspondingly, the valve 17 is shown in the closed ornonrunning position. Both va res 18 and 18 are normally in the openposition. The fact that the valve 17 is shown in the open position doesnot necessarily result in the application of the air brakes, for thevalve ofrelay 16 is normally closed.

In the operation of the. circuits and instruments shown in Fig. 2,direct current passes from the third rail T of Fig. 1 through oneor moreof the shoes 9 and thence through conductor 11 and the impedance bond 10to conductor 10, and thence through conductor 19 to the armature ofvalve relay 1G and through the front stop of that relay and the magnetcoil of circuit breaker 13 to the frame of the car and so to the wheelsand axles and track rail R thence through one or another of conductors20 (Fig. 1) back to the second- .9 of the transformer from such traincontrol current was derived. The alternating current in the third rail Talso passes through one or more. of the shoes -9, and wire 11, tocontact point 21 of switch 17 and thence through the arm of that switchand contact point 22 to the magnet coils of relay 16 and thence toground at 20. hen two or more cars are which coupled together to form atrain, it is cusing trainbus of another car, while per- -m1tt1ng,passageof direct current from the train bus of one car to the train bus ofanother car and so on. The alternating current so received through oneor another of the shoes 9, and passing through conductor 11 and contactpoints 21 and 22 of switch 17 passes thence through the conductor 23 Iand condenser 24 to the magnet coils of 'alve relay 1G and thence toground at 20; this magnet being held energized and its air brake valveclosed, so long as the supply of alternating current continues. Butshould the alternating current fail (as will occur, for example, whenthe car or train' exceeds predetermined speed and passes into a blockbefore the delay action line relay L or L etc; of that block has closedits. front contact) then the resulting deiinergization of the magnet ofvalve relay 16 will cause the air brake valve of that relav to open, soapplying the brakes, and at the same time will release the armature ofcircuit breaker 13, thus cutting off power current from the motors, andso stopping the car or train. Upon reestablishment of supply ofalternating current, the magnet of valve relay 16 will be energizedagain, thus closing the air brake valve of that relay and closing thecircuit through the coils of the circuit breaker 13. This circuitbreaker may be understood to be one the armature of which is restored byhand.

The condens r 21 excludes direct current from the magnet of air brakevalve relay 16.

The valve switches 18 and 18' are provided to permit a train to proceedin case of necessity, even though the alternating train-control currentis cut off. These switches 18 and 18 are shown as of the push-buttontype; though of course they may be of any type. Depressing one of theseswitches closes the corresponding air brakeline valve forming a part ofthat switch. Supposing the car, the circuits of which are shown in Fig.2, to be operated from the right hand end (switches 17 and 17' beingthen inthe positions shown in Fig. and supposing the car to have beenarrested through breaking of the alternating current circuit by one ofthe line relays L L etc.; in that case the magnet of relay 16 will be(leenergized and the air brake valve of that relay open, the brakesbeing applied and the circuit breaker 13 also being open: the operatordepresses the switch 18, so closing the air brake line and releasing thebrakes. in so doing he closes a circuit 2526 across the terminals ofconductors lat and 15, so accomplishing the same result as it thecircuit breaker 13 were closed; the car or train being thereby permittedto proceed.

Eventually, a condenser '27 (Fig. 1) 'may be interposed in thetrain-control-circuit to exclude propulsion current from the traincontrol circuit."

Current for the track circuits may be derived from any suitable source;but I have indicated each transformer S, S, etc., as provided with athird secondary coil 8 connected to the track rails ofthe correspondingblock;

While the use of direct current for propulsion current, and alternatiingcurrent for train control current, has many mlvantages, yet in a broadsense it is immaterial which type of current be used for propulsion, andwhich type for train control. In Figs. 3 and 4 I have indicated anarrangement. wherein direct current is employed for train control andalternating current for propulsion. R and R are, as before the trackrails, R being divided into block sections, and T is the third rail ortrain-control conductor, likewise divided into block sections. F" is thealternating current feed line for propulsion current, and S" the linethrough which direct train control'current is supplied. L, L, etc., aredirect current line relays and TR and TR", etc, are direct current trackrelays. The circuits are substantially the same as above described withreference to Figs. 1 and 2, except that the several sections of thethird rail are connected through condensers 28 which permit the passageof the alternating propul sion current, but excluding the direct traincontrol current. 29 are interposed in the train control circuits toexclude the alternating propulsion current from such circuits.

30 are provided for excluding the direct train control current from thatbus, and inductive resistance 31 is provided in the circuit of the valverelay 16 for excluding the alternating propulsion current from thatrclav. 1

Obviously, instead of employing direct 4 Referring to Fig. 4, in thetrain line bus 10 condensers,

and alternating current, either the direct trol circuits, to make eachcircuit resonant to the current of the particular frequency pertainingto that .circuitand thereby to excludefrom such circuit thecurrent ofthe other frequency. The circuits of Figs. 5 and 6 will be understoodreadily from consideration of the previous figures.

\Vhat I claim is: i

1. A railway train control system cornprising in combination a track, aconductor exteiiding along said track and divided into block sections.means for the supply of train control current for each such block,comprising a time-elementcircuit controller, and train actuated meansfor each block, each suchtrain actuated means controlling the saidtime-element circuit controller of its own block and. the saidtime-element circuit controller of a block in advance.

2. A railway train control system comprising in combination a track, aconductor extending along said track and divided into block sections,means for the supply of train control current for each such blockcomprising a time-element circuit controller, and train actuated meansfor each such block, each such train actuated means controlling the saidtime-element circuit controller of 5 Also, inductive resistances -jcontroller of a block in advance, and the said time-element circuitcontroller .of a block in rear, the time-element circuit controllerpteach block also controlling the tnne-elei'nent circuit controller of ablock in rear. I

'4. A railway train control system comprising in combination a track, aconductor extending along said track and divided into block sections,means for the supply of train control current for each such blockcomprising a time-element circuit controller, and train actuated meansfor each such block. each such train actuated means controlling the saidtime-element circuit controller of its own block, and the saidtime-element circuit controller of a block in advance, and the saidtime-element circuit controller of a block irrear, the train actuatedmeans and time-element circuit controller of each block jointly;controlling the time element circuit controller of a block in rear.

5. A railway train control system comprising in combination a track,- aconductor extending along said track and divided into block sections.means for the supply of train control current for each such block,comprising a time-clement relay and train actuated means for each blockand a circuit controlled thereby and passing through the magnet ot' thetime-element relay ot' a block in advance.

6. A railway train control system comprising in combination a track, aconductor extending along said track and divided into block sections,means for the supply of train control current for each such block,comprising a timeelement relay and train actuated means for each blockand a circuit controlled thereby and passing through the magnet of thetime-element relay ot' a block in advance. each such train actuatedmeans also controlling the time-clement relay of its own block. p

7. A railway train control system comprising in combination a track, aconductonextending along said track and divided into block scctions,neans tor the supply of train .control current for each such block.comp'risin a time-elei'nent relay, and train actuated inc-ans for eachblock, and a circuit .tor

each time-clement relay passing through a contact of the train actuatedmeans of a block in rear and through contacts of the train actuatedmeans and time-element relay of a. block in advance.

8. A railway'train control system comprising in combination a track, aconductor extending along said track and divided into block sections,means for the supply of train control current for each such block,comprising a time-element relay, and train actuated means for eachblock, and a circuit for each time-element relay passing through acontact of the train actuated means of a block in rear and throughcontacts of the train actuated means and time-ele1nent relay of a blockin advance. each such train actuated means comprising means for holdingthe time-element relay of the corresponding block in position for thesupply of train control current to that block.

9. A 'ailway train control system coinprising in combination a track, acontact conductor extending along said track and divided into blocksections, circuits, one for each such block, for the supply of traincontrolcurrent to the several blocks of that conductor. a delay actionrelay for each such block section controlling the correspondingtrain-control cm'rent'circuit, means located at a predetermined distancein advance or" f each such block: section. and arranged to be actuated la pa sing train and when so actuated to cause the relay correspoi-ulingto such block to act to close the train control circuit of that block.and means for hold- 'ing each such relay in closed circuit posimeanstherefor arranged to cause such relay to be operated by a passing train,and a circuit connecting each such second relay to the delay actionrelay of a block ahead. each such second relay arranged when actuated bya passing train to causethe delay action relay ot' the said block aheadto act to close r the corresponding train control c1,rcu1t ot thatblock, each such second relay also arranged when actuating by a passingtrain to hold in closed circuit position the delay action relay of itsown block. v

11. A railway train control system comprising in combination a track; acontact conductor extending aldng' said track and divided into blocksections, circuits, one for each such block, for the supply of traincontrol current to the several blocks of that conductor, a delay action.relay for each such block section controlling the-corresponding apassing train, to cause the delay action relay of the said block aheadto act to close the corresponding train control circuit of that block,provided the said advance block be not occupied, each such second relayfurther comprising means for holding in closed circuit position the saiddelay action relay of its own block While that block is occupied.

12. A railway train control system com prising in combination a track, acontact conductor extending along said track and divided into blocksections, means for the supply of train control current and propulsioncurrent to each block, such train control current and propulsion currentbeing the one an alternating current and the other a direct current, adelay action relay for each such block section controlling the supply oftrain control current to that block, a second relay for each such blocksection and operating means therefor arranged to cause each such secondrelay to be operated by a passing train, and a circuit connecting eachsuch second relay to the delay action relay of a block ahead and thenceextending through a normally closed contact of the second relay of afurther advance block and through a normally closed contact of the delayaction relayofsuch further advance block, each such second relayarranged, wvhen actuated by a passing train, to cause the delay actonrelay qr the. said block ahead to act to CLOSE the corresponding traincontrol circuit of that block, provided the said advance block be notoccupied, each such second relay further comprising means for holding inclosed circuit position the said delay action relay of its own blockWhile that block is occupied.

13. A railway train control system comprising in combination a track, acontact conductor extending along said track and divided into blocksections, means for the supply of train control current and propulsioncurrent to each block, such train control current and propulsion currentbeing the one an alternating current and the other a d' tot current,said contact conductor comraoaaea prising means permitting the passageof propulsion current from section to section and for preventing passageof train control current from section to section, a delay action relayfor each such block section controlling the supply of train controlcurrent to thatblock, a second relay for each such block section andoperating means therefor arranged to cause each such second relay to beoperated by a passing t am, and a circuit connecting each such secondrelay to the delay action relay of a block ahead and thence extendingthrough a normally closed contact of the second relay of a furtheradvance block and through a normally closed contact of the delay actionrelay of such further advance block, each such second relay arranged,When actuated by a passing train, to cause the delay action relay of thesaid block ahead to act to close the corresponding train controlcircuitof that block,

provided the said advance block be not octrol current being the onedirect current and the other alternating current, of train equipmentcomprising contact means adapted to make contact with that conductor, atrain control relay and a circuit therefor con-' nected to said contactmeans, said circuit comprising means for excluding the propulsioncurrent from said tram control relay, and brake-operating means andpower-con trolling means controlled by that relay, andillo meansarranged when operated to make ineffective the operation of suchintake-operating means and power controlling means.

15. in a railway train control system, train equipment comprisingcontact means adapted to make contact with a conductor extending along atrack, a tr incontrol relay and a .circuit therefor connected to saidcontact means, a brake-line containing a valve operated by said relay,and one or more brake-line valve switches each ar; ranged in oneposition to open the brake-line beyond the relay-opcrated valve and insuch position to close a contact in said relay .circui t and in anotherposition to close said brakcdine and open a contact in such relaycircuit. 7

16. hr a railway train control system, train equipment comprisingcontact means adapted. to make contact with a conductor ex its tendingalong a track. a train-control relay and a circuit therefor connected tosaid contact means, said circuit including means for the exclusion ofpropulsion current from said relay, a brakeline containing a valveoperated by said relay. and one or more brake-line 'alve switches eacharranged in one position to open the brake-line beyond therelay-operated 'valve and in such position to close a contact in saidrelay circuit,

and in another position to close said brake- -line and open a contact insuch relay circuit.

17. In a railway train control system. train equipment comprisingcontact-means adapted to make contact with a conductor extending along'atrack. a train control rclay and a circuit therefor connected to saidcontact means. said circuit including means for the exclusion ofpropulsion current from said relay. a brake-line containing a valveoperated by said relay. a circuit breaker also controlled by said relay.and a plurality of brake-line valve switches each arranged in runningposition to open the brake-line beyond the relay-operated valve and insuch position to close a contact in said relay circuit. and in anotherposition to close said brake-line and open a contact. in such relaycircuit. said switches arranged when in the non-running; position toclose a shunt across the said circuit reaker.

1b. railway train control systei'n comprising in combination a track. acoiuluctor extending along such track and divided into block sections,means for the supply of train control current for each such block.comprisin; a time-element circuit controller, train actuated means forach block. each such train actuated means controlling the said timeelement circuit controller of-its (.wn block, and the said time-elementcir cuit controller of :i block in advance. train equipment comprisingcontact means adapted to make contact with that conductor. a traincontrol relay and a' circuit therefor connected to said contact means,and brakeoperating' means and power controlling means controlled by thatrelay.

19. A railway train "control system comrising in combination atrack. aconductor extending along such track and divided into arranged whenoperatedto make ineffective the operation of such brakeoperating meansand power-controlling means.

20. In a railway train control system, the con'ibination with aconductor extending along a railway track and divided into blocksections, means for the supply of propulsion current to that conductor.and means for the supply of train control current to that conductoandfor the control of such train control current to effect control of atrain.

said propulsion current and train control.

that conductor and for the control of such train control current toeffect control of a train. said propulsion current and train controlcurrent being the one direct current and the other alternation current.of train equip ment comprising contact means adapted to make contactwith that conductor. a train control relay and a circuit thereforconnected to said contact means. said circuit com prising means forexcluding the propulsion current from said train control relay. andbralie-operating means and power-controlling: means controlled by thatrelay.

'2. A railway train control system romprisingr in combination a track. aconductor extending along said track and divided into block sections,means for the supply of propulsion current to said conductor. means forthe supply of train control current to -ach block of such conductor.comprising a timeelement circuit controller. and train actuated meansfor each block. ach such train actuated means controlling the saidlime-element circuit controller of its'own block. and the saidtime-element circuit controller of a block in adyance. means forexcluding: the train control current supply to any one block from theadjacent blocks. and train equipment comprising contact means adapted tomake contact with that coi'iductor. a train control relay and a circuittherefor ,connected to said contact means. said circuit comprising meansfor excluding the propulsion current from said train control relay, andmeans controlled by said train control ,relay for the control of thetrain.

"23. in a railway train control system,

train equipment comprising two contact. jncans insulated one from theother and" adapted the one to make contact with one conductor extendingalong a track, and the other to make contact with another conductorextending along such track, a train-control relay and an energizingcircuit therefor connected at opposite ends to said two contact means,brake-controlling means operated by said relay, and one or more switchescontrolling the energizing circuit of said relay and also controllingbrake-applying means.

24.111 a railway train control system, tram equipment comprising tWocontact means insulated one from the other andone adapted to makecontact with one conductor extending along a track, and the otheradapted to make cont-act with another conductor extending along suchtrack, a traincontrol relay and an energizing circuit therefor connectedat opposite ends to said two contact means, a brake-line containing avalve operated by said relay, and one or more brake-line valve switchescontrolling the energizing circult of said relay and each arranged inone position to open the brake line beyond the relay-operated valve andin such position to close a Contact in such re lay energizing circuit,and in another position to close such brake line and open a contact 1nsuch relay circuit.

25. In a railway train control system,-

train equipment comprising two contact means insulated one from theother and one adapted to make contact with one conductor extending alonga track, and the other adapted to make contact with another conductorextending along such track, a train-control relay and an energizingcircuit therefor connected at opposite ends to said two contact means, abrake-line containing a valve operated by said relay, and one or morebrakeline valve switches controlling the energizing circuit of saidrelay and each arranged in one position to open the brake line beyondthe relay-operated valve and in such posi tion to close a contact insuch relay ener-- gizingcircuit, and in another position to close suchbrake line and open a contact in such relay .circuit, a train control,imircuit controlled by said train control relay, and one -or moreemergency valve switches arranged when operated to closethe brake lineand to close a bridge across the train-con-

